First of all, I would give this movie more around 3.5-4 stars. It lies somewhere in that range. The cinematography was absolutely stunning. From the house, to the nature, down to the costumes and color schemes, it was perfect. The same goes for the acting. All three of the main actors, (Mackenzie Davis, Finn Wolfhard, and Brooklynn Prince), were incredible. They all fit their characters so well, and played their parts beautifully.
The first three quarters of the movie were interesting, captivating, and psychologically horrifying. There was jump scares, character development, and twists and turns that kept you on your toes.
The ending is another story. It is obvious that the director ended the film this way on purpose. It makes you feel as though you are going insane with Kate (the main character). By the end of the movie, you won't know what was real or who to trust. The ending leaves the story open to interpretation, and I have some theories of what I think the ending was designed to show. However, the ending is almost TOO open. You are offered hardly any closure, and although I enjoy making theories and analyzing films, most people don't like it. People WANT closure in films, and unfortunately this film offered none. I personally, would have preferred if they extended the movie even just another minute, because one extra scene could have clarified the ending a lot more.
This is a great movie and I highly recommend seeing it. I went into the film with and open mind and ultimately was not disappointed. The critics were very harsh on this movie. It's definitely deserving of at least 50% rotten tomatoes in my opinion. If you can accept that the ending is very abstract, you'll probably really enjoy it. :)